What kind of cells are in these packs?

[skellyo]

Too expensive IMO. You can pick up several well known brands of equivalent packs cheaper than that. Some examples:

Neu 5S 30C 5000mAh $235
PolyRC 5S 30C 5000mAh $221
PolyQuest 5S 25C 6000mAh $260
RCM 5S 25C 5000mAh $225
Elite 5S 35C 5000mAh $220

Given those options, I personally wouldn't even think of spending $280 on a pack from a company that doesn't have a solid reputation in the 1/8th BL community.